In this article, we used plane-wave density functional theory to investigate the elasticity, anisotropy, and minimum thermal conductivities of baddeleyite type IVTMO2(m-TiO2, m-ZrO2, and m-HfO2). The elastic constants...In this article, we used plane-wave density functional theory to investigate the elasticity, anisotropy, and minimum thermal conductivities of baddeleyite type IVTMO2(m-TiO2, m-ZrO2, and m-HfO2). The elastic constants and modulus, Poisson's ratio, hardness, sound speed, Debye temperature, and minimum thermal conductivities at high temperature were calculated. These calculations show that m-MO2 is not superhard, with a hardness range of about 8–13 GPa. Among these materials, m-Ti O2 is the hardest, while m-Hf O2 is the least hard. Their elastic and plastic anisotropy are given in detail. Moreover, the m-Hf O2 thin film is the most likely to develop microcracks during preparation because it has the highest elastic anisotropy. Among the three dioxides, m-HfO2 is the best thermal barrier because it has the lowest thermal conductivity.展开更多
基金supported by the National Natural Science Foundation of China (51171156)the Fundamental Research Funds for the Central Universities (XDJK2014C008)
文摘In this article, we used plane-wave density functional theory to investigate the elasticity, anisotropy, and minimum thermal conductivities of baddeleyite type IVTMO2(m-TiO2, m-ZrO2, and m-HfO2). The elastic constants and modulus, Poisson's ratio, hardness, sound speed, Debye temperature, and minimum thermal conductivities at high temperature were calculated. These calculations show that m-MO2 is not superhard, with a hardness range of about 8–13 GPa. Among these materials, m-Ti O2 is the hardest, while m-Hf O2 is the least hard. Their elastic and plastic anisotropy are given in detail. Moreover, the m-Hf O2 thin film is the most likely to develop microcracks during preparation because it has the highest elastic anisotropy. Among the three dioxides, m-HfO2 is the best thermal barrier because it has the lowest thermal conductivity.
